# Newbie question on search path

**URL:** <https://discourse.julialang.org/t/newbie-question-on-search-path/12384>\
**Category:** New to Julia\
**Created:** [July 15, 2018, 4:12am UTC](https://discourse.julialang.org/t/newbie-question-on-search-path/12384 "2018-07-15T04:12:24Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![rdeits](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/rdeits/32/286_2.png) [@rdeits](https://discourse.julialang.org/u/rdeits)\
**Post date:** [July 15, 2018, 4:21am UTC](https://discourse.julialang.org/t/newbie-question-on-search-path/12384/2 "2018-07-15T04:21:45Z")

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Welcome!

Julia code typically uses more, smaller functions, with many functions living within a single file. You don’t _have_ to do that, but I find that short functions are easier to describe, understand, and test. The fact that MATLAB only allows a single exported function per file, is, in my opinion, a significant downside to the language.

Since Julia code tends to have many functions, we need some way to organize them. The way we do that is with Modules. You can read about Modules in the manual here: [https://docs.julialang.org/en/stable/manual/modules/](https://docs.julialang.org/en/stable/manual/modules/)

For example, you can make a module by creating a file called `Foo.jl` and adding the following:

```julia
module Foo

function f(x)
  println(x)
end

function g(x, y)
  x + y
end

end

```

To use the module you’ve just defined, you need to tell Julia where to look for it. See: [https://docs.julialang.org/en/stable/manual/modules/#Module-file-paths-1](https://docs.julialang.org/en/stable/manual/modules/#Module-file-paths-1) All you need to do is add the folder containing `Foo.jl` to your `LOAD_PATH` variable with `push!(LOAD_PATH, "/path/to/folder")`. Then you can load your module with:

```julia
using Foo

Foo.f(1.0)

```

Note that the name of the module matches the name of the file: `module Foo` is in `Foo.jl`. The filename matters, and when you do `using Foo` Julia will expect to find `Foo.jl` or `Foo/src/Foo.jl` somewhere in `LOAD_PATH`.

If you want to call the `f` function without the `Foo.` prefix, you can modify your module:

```julia
module Foo

export f

function f(x)
  println(x)
end

function g(x, y)
  x + y
end

end

```

Then you can do:

```julia
using Foo
f(1.0)

```

If you don’t want to do the `push!(LOAD_PATH, ...)` every time you start Julia, you can either set the `JULIA_LOAD_PATH` environment variable, or you can just add that `push!` statement to your `~/.juliarc.jl` file. For more info see: [https://docs.julialang.org/en/stable/manual/getting-started/#Getting-Started-1](https://docs.julialang.org/en/stable/manual/getting-started/#Getting-Started-1)

If your module starts to get too big to comfortably remain in a single file, you can split it up into files however you like. See: [https://docs.julialang.org/en/stable/manual/modules/#Modules-and-files-1](https://docs.julialang.org/en/stable/manual/modules/#Modules-and-files-1)

Finally, as your code matures to the point where you’d like to share it with other people, you can turn it into a package, which other people will be able to install with `Pkg.add()` or `Pkg.clone()`. For more info see [https://docs.julialang.org/en/stable/manual/packages/](https://docs.julialang.org/en/stable/manual/packages/)

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